Research shows potential of antibiotic alternative for livestock

Scientists at the University of Wisconsin-Madison have developed an antibiotic-free method to protect animals raised for food against common infections such as the diarrheal disease coccidiosis. This comes at a time when major fast food chains and food retailers are announcing plans to make major cuts in antibiotic use in meat production as consumers’ concern about antibiotic resistance bacteria continues to grow.

A recent article states that currently, about 80% of antibiotics in the U.S. are used in livestock production because they both protect against disease and accelerate weight gain in many farm animals. However, these antibiotics can only control disease and bacteria for so long before they evolve and defeat the drugs used, professor of animal science, Mark Cook said in the article.

Cook’s current work focuses on a fundamental immune “off-switch” called Interleukin 10 or IL-10, manipulated by bacteria and many other pathogens to defeat the immune system during infection. He and animal science associate researcher, Jordan Sand, have learned to disable this switch inside the intestine, the site of major farm animal infections.

According to the article, Cook vaccinates laying hens to create antibodies to IL-10. The hens put the antibody in eggs and it is then sprayed on the feed of the animals he wants to protect as well. The antibody neutralizes the IL-10 off-switch in those animals, allowing their immune systems to better fight disease.

In an experiment with 300,000 chickens, those that ate the antibody-bearing material were fully protected against coccidiosis. Smaller tests with larger animals also show promise as researchers were able to halved the rate of bovine respiratory disease in beef steers by feeding them the IL-10 antibody for 14 days.

“That’s a very enticing early result,” Dan Schaefer, professor of animal science and researcher in the study, said in the article. “Bovine respiratory disease is the number one health risk for feeder cattle coming into a confinement situation.”

In addition, a test of newborn dairy calves found less than half as much respiratory disease in the calves that ate the antibody for 10 days compared to those that did not. The treated calves also showed less shedding of Cryptosporidium parvum, a protozoa that causes diarrhea.

“These diseases cause long-term reproduction, production and growth impairments in livestock,” Sheila McGuirk, a professor of medical sciences and researcher involved in the study, said in the article. “The affected animals are suboptimal in health, performance and profitability. To have something affordable, safe and nonantibiotic that controls these very important diseases is absolutely awesome. We are eager to study this further.”

“People have manipulated the immune system for decades, but we are doing it in the gut. Nobody has done that before,” Cook added. “We are getting encouraging data from dairy and beef… and we know how it works. The market is interested, and now it’s a matter of making a product.”